In the printing field, the impact type printer has been the predominant apparatus for providing increased throughput of printed information. The impact printers have included the dot matrix type wherein individual print wires are driven from a home position to a printing position by individual and separate drivers. The impact printers also have included the full character type wherein individual type elements are caused to be driven against a ribbon and paper or like record media adjacent and in contact with a platen.
The typical and well-known arrangement in a printing operation provides for transfer of a portion of the ink from the ribbon to result in a mark or image on the paper. Another arrangement includes the use of carbonless paper wherein the impact from a print wire or a type element causes rupture of encapsulated material for marking the paper. Also known are printing inks which contain magnetic particles wherein certain of the particles are transferred to the record media for encoding characters in manner and fashion so as to be machine readable in a subsequent operation. One of the known encoding systems is MICR (Magnetic Ink Character Recognition) utilizing the manner of operation as just mentioned.
While the impact printing method has dominated the industry, one disadvantage of this type printing is the noise level which is attained during printing operation. Many efforts have been made to reduce the high noise levels by use of sound absorbing or cushioning materials or by isolating the printing apparatus.
More recently, the advent of thermal printing which effectively and significantly reduces the noise levels has brought about the requirements for heating of extremely precise areas of the record media by use of relatively high currents. The intense heating of the localized areas causes transfer of ink from a ribbon onto the paper. Alternatively, the paper may be of the thermal type which includes materials that are responsive to the generated heat.
The use of thermal printing with different color inks has also been proposed and applied in certain technologies. An application for thermal printing has included the postal system which makes use of one or more fluorescent pigments.
Representative documentation in the area of nonimpact printing includes U.S. Pat. No. 3,117,018, issued to E. Strauss on Jan. 7, 1964, which discloses a color transfer medium and method of producing the same by applying a coating consisting of a polycarbonate, a solvent, a plasticizer and a pigment, and then drying the coating to form a solid transfer layer.
U.S. Pat. No. 4,663,278, issued to J. H. Blose et al. on May 16, 1972, discloses a thermal transfer medium having a base with a transferable coating composition of a cellulosic polymer, a thermoplastic resin, a plasticizer, and a sensible dye or oxide pigment material.
U.S. Pat. No. 4,251,276, issued to W. I. Ferree et al. on Feb. 17, 1981, discloses a transfer ribbon having a substrate coated with a thermally-active ink composition comprising a thermally-stable polymer, an oil-gelling agent, and an oil-dissolving medium or plasticizer present in a percentage by weight of the total nonvolatile components.
U.S. Pat. No. 4,272,292, issued to S. Mizuno et al. on June 9, 1981, discloses an ink composition comprising at least one of the carbinol bases of the basic dyes, a strong base, a binder and a solvent.
U.S. Pat. No. 4,461,586, issued to T. Kawanishi et al. on July 24, 1984, discloses an ink ribbon having an electroconductive base layer comprising a binder resin and an electroconductive material, and an electroconductive ink layer comprising a thermoplastic material and an electroconductive material.
U.S. Pat. No. 4,474,844, issued to T. Omori et al. on October 1984, discloses a heat transfer recording medium comprising tissue paper with a thermal-responsive ink layer. The paper thickness, density and smoothness are set out by measurement and water content is a percentage of the ink layer.
U.S. Pat. No. 4,614,682, issued to A. Suzuki et al. on Sept. 30, 1986, discloses a thermo-sensitive image transfer recording medium comprising a support and an ink layer consisting of a dye, a binder and a pigment of needle-like crystal form.
U.S. Pat. No. 4,624,891, issued to H. Sato et al. on Nov. 25, 1986, discloses heat transfer material comprising a micro-network porous resin of thermoplastic resin and heat fusible gel ink which comprises a colorant, an oil and a gelatin agent.
And, U.S. Pat. No. 4,627,997, issued to Y. Ide on Dec. 9, 1986, discloses a thermal transfer recording medium comprising an inking layer of a fluorescent substance, a coloring agent, waxes, and a binder on a substrate.